percona-xtrabackup: revision bump (protobuf 21.2)
percona-xtrabackup: revision bump (protobuf 21.2)

Conflict with `percona-server` to avoid a `brew install` failure in CI.

This needs a proper fix, but we use this for now to unblock the
`protobuf` version bump.

stgraber/homebrew-core,nandub/homebrew-core,adam-moss/homebrew-core,zyedidia/homebrew-core,stgraber/homebrew-core,filcab/homebrew-core,chrisfinazzo/homebrew-core,sjackman/homebrew-core,nandub/homebrew-core,Homebrew/homebrew-core,zyedidia/homebrew-core,lemzwerg/homebrew-core,filcab/homebrew-core,makigumo/homebrew-core,Homebrew/homebrew-core,nbari/homebrew-core,adam-moss/homebrew-core,nbari/homebrew-core,sjackman/homebrew-core,lemzwerg/homebrew-core,makigumo/homebrew-core,chrisfinazzo/homebrew-core